A wide variety of homopolyesters and copolyesters are currently being used in making fibers and molded articles. In selecting a polyester for a given application, its physical and chemical properties are taken into account. For instance, polyethylene terephthalate (PET) has an excellent combination of properties for utilization in making reinforcements for rubber articles, such as tire cord. Even though PET has an excellent overall combination of properties for utilization in making tire cord, it would be desirable for it to have higher tenacity and modulus in order to attain better durability and stiffness. On the other hand, even though fibers made utilizing known anisotropic melt polyesters have high tenacity and modulus, it would be desirable for them to have higher elongation and toughness in order to attain better flex life in tires.